ES2391973T3 - Supported polymerization catalysts - Google Patents

Abstract

A supported polymerization catalyst system prepared by a method comprising the following steps: (i) adding a cocatalyst to a porous support, (ii) mixing a polymerization catalyst with a polymerizable monomer, and (iii) contacting the components together resulting from steps (i) and (ii) where the ratio of the polymerizable monomer to the polymerization catalyst is in the range of 1: 1 to 250: 1.

Description

Supported polymerization catalysts

The present invention relates to supported catalysts suitable for the polymerization of olefins and in particular with supported metallocene catalysts that provide advantages for operation in the gas phase processes for the polymerization of ethylene or the copolymerization of ethylene and olefins to which They have 3 to 10 carbon atoms.

In recent years there have been many advances in the production of polyolefin homopolymers and copolymers due to the introduction of metallocene catalysts. Metallocene catalysts generally offer the benefit of greater activity than traditional Ziegler catalysts and are usually described as catalysts that have a unique site in nature. Several different families of metallocene complexes have been developed. In recent years catalysts based on bis (cyclopentadienyl) metal complexes have been developed, examples of which can be found in EP 129368 or EP 206794. More recently, complexes having a single or mono cyclopentadienyl ring have been developed. These complexes have been referred to as 'restricted geometry' complexes and examples of these complexes can be found

15 in EP 416815 or EP 420436. In both complexes the metal atom for example zirconium is in the highest oxidation state.

However, other complexes have been developed in which the metal atom may be in a reduced oxidation state. Examples of the bis (cyclopentadienyl) and mono (cyclopentadienyl) complexes have been described in WO 96/04290 and WO 95/00526 respectively.

The above metallocene complexes are used for polymerization in the presence of a co-catalyst or activator. Normally the activators are aluminoxanes, in particular methyl aluminoxane or alternatively they can be compounds based on boron compounds. Examples of the latter are borates such as tetrafluorophenylborates or triarylborane or substituted trialkyl tetraphenyl ammonium- or such as tris (pentafluorophenyl) borane. Catalyst systems incorporating borate activators are described in EP documents.

25 561479, EP 418044 and EP 551277.

The above metallocene complexes can be used for the polymerization of olefins in solution, suspension or gas phase. When used in the gas or suspension phase the metallocene complex and / or the activator are adequately supported. Typical supports include inorganic oxides, for example, polymeric or silica supports can be used alternatively.

Examples for the preparation of supported metallocene catalysts for the polymerization of olefins can be found in WO 94/26793, WO 95/07939, WO 96/00245, WO 96/04318, WO 97/02297 and EP 642536.

WO 98/27119 describes the components of the support catalyst comprising ionic compounds comprising a cation and an anion in which the anion contains at least one substituent which

35 comprises a structural unit that has an active hydrogen. In this description, supported metallocene catalysts are exemplified in which the catalyst is prepared by treating the above-mentioned ionic compound with a trialkylaluminum compound followed by subsequent treatment with the support and the metallocene.

WO 98/27119 also describes a method for activating a substantially inactive catalyst precursor comprising (a) an ionic compound comprising a cation and an anion containing at least one

A substituent comprising a structural unit having an active hydrogen, (b) a transition metal compound and optionally, (c) a support by treatment with an organometallic compound thereby forming an active catalyst.

Various methods have been used to prepare supported catalysts of this type. For example, WO 98/27119 describes various methods for preparing the supported catalysts described therein in

The support is impregnated with the ionic compound. The volume of the ionic compound may correspond from 20 percent by volume to more than 200 percent by volume of the total pore volume of the support. In a preferred preparation route the volume of the ionic compound solution does not substantially exceed, and is preferably equal to, the total pore volume of the support. Such preparation methods can be referred to as incipient precipitation or incipient moisture techniques.

US 6225423 describes the reaction product of a transition metal compound with an unsaturated organic compound such as 1-hexene and wherein the reaction product is then contacted with a suitable solvent with an organoaluminum compound and optionally with a carrier material.

US 5912202 describes the contact between a single site catalyst precursor with an activating cocatalyst before, during or after contact of the single site precursor with a weak coordinating electron donor that does not substantially polymerize during the contact stage.

Macromolecular Rapid Communications 1998, 19.505-509 describes the preparation of a number of silica supported metallocene catalysts. The exemplified systems describe the addition of a metallocene / 1-hexene solution to a silica supported aluminoxane or the addition of a metallocene to the silica supported aluminoxane followed by the addition of 1-hexene.

More recently, Macromolecular Rapid Communications 2001, 22, 1427-1431 describes the preparation of supported metallocene catalysts by impregnating up to the pore volume of a silica support with a pre-mixed 1-hexene solution of co- and procatalysts. The exemplified systems are bis (cyclopentadienyl) zirconium dichloride / methyl aluminoxane supported by silica for suspension polymerization. However, such systems do not show long-term storage stability and after a few days they are inactive for polymerizations.

Our previous application WO 04/020487 describes the addition of a polymerizable monomer to the support before coming into contact with one or both between the polymerization catalyst and the co-catalyst. This procedure results in an improved support catalyst system that has improved activity and is stable for extended periods.

US 6458904 describes the preparation of metallocene catalysts by contacting specific metallocene complexes with alkyl-1-enos followed by reaction with the ionic compounds. Optionally, a support material can subsequently be added to the metallocene / ionic compound mixture.

We now find that premixing the polymerizable monomer with the polymerization catalyst component before contact with the supported co-catalyst leads to advantages in activity and stability.

Thus, according to the present invention, a supported polymerization catalyst system prepared by a method comprising the following steps is provided:

(i)

 add a cocatalyst to a porous support,

(ii)

mixing a polymerization catalyst with a polymerizable monomer, and

(iii) contact the components together that result from steps (i) and (ii).

Suitable porous support materials include inorganic metal oxides or alternatively polymeric supports can be used for example polyethylene, polypropylene, clays, zeolites, etc.

Suitable inorganic metal oxides are SiO2, Al2O3, MgO, ZrO2, TiO2, B2O3, CaO, ZnO and mixtures thereof.

The most preferred support material for use with the supported catalysts according to the method of the present invention is silica. Suitable silicas include Ineos ES70 and Grace Davison 948 silicas.

The material support can be subjected to heat treatment and / or chemical treatment to reduce the water content or the hydroxyl content of the material support. Normally the chemical dehydration agents are reactive metal hydrides, aluminum alkyl and halides. Before use, the material support can be treated at 100 ° C to 1000 ° C and preferably 200 to 850 ° C in an inert atmosphere under reduced pressure.

Porous supports are preferably pretreated with an organometallic compound preferably an organoaluminum compound and more preferably with a trialkylaluminum compound in a diluted solvent.

Preferred trialkylaluminum compounds are triethylaluminum or triisobutylaluminum.

The material support is pretreated with the organometallic compound at a temperature of -20 ° C to 150 ° C and preferably from 20 ° C to 100 ° C.

Other suitable supports may be those described in our application GB03 / 05207. This application describes the use of pretreated supports with a source of a transition metal atom such as metal iron or copper salts.

Polymerizable monomers suitable for use with the method of the present invention include ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, styrene, butadiene, and polar monomers for example vinyl acetate, methyl methacrylate , etc. Preferred monomers are those having 2 to 10 carbon atoms in particular ethylene, propylene, 1-butene or 1-hexene.

Alternatively, a combination of one or more monomers can be used, for example ethylene / 1-hexene.

The preferred polymerizable monomer for use in the present invention is 1-hexene.

The polymerizable monomer is suitably used in liquid form or alternatively it can be used in a suitable solvent. Suitable solvents include for example heptane.

The polymerizable monomer and the polymerization catalyst are used in a ratio of 1: 1 to 250: 1 and more preferably in the ratio 20: 1 to 80: 1.

The polymerization catalyst component according to the present invention may suitably be any polymerization catalyst used in conjunction with a porous support in the present suitable co-catalyst.

The polymerization catalyst may normally be the transition metal compound of Groups IIIA to IIB of the Periodic Table of the Elements (IUPAC Version). Examples of such transition metal compounds are traditional Ziegler Natta, vanadium and Phillips type catalysts well known in the art.

Traditional Ziegler Natta catalysts include the transition metal compounds of the IVA-VIA Groups, in particular catalysts based on titanium compounds of the formula MRx wherein M is titanium and R is halogen or a hydrocarbyloxy group and x is the state of metal oxidation Such conventional type catalysts include TiCl4, TiBr4, Ti (OEt) 3Cl, Ti (OEt) 2Br2 and the like. Traditional Ziegler Natta catalysts are described in more detail in "Ziegler-Natta Catalysts and Polimerisation" by J. Boor, Academic Press, New York, 1979.

Vanadium-based catalysts include vanadyl halides for example VCl4, and alkoxy halides and alkoxides such as VOCl3, VOCl2 (OBu), VCl3 (OBu) and the like.

Conventional chromium compounds referred to as Phillips type catalysts include CrO3, chromocene, silyl chromate and the like and are described in US 4124532, US 4302565.

Other conventional transition metal compounds are those based on complex magnesium / titanium electron donor complexes described for example in US 4302565.

Other suitable transition metal compounds are those based on the late transition metals (LTM) of Group VIII for example compounds containing iron, nickel, manganese, ruthenium, cobalt or palladium metals. Examples of such compounds are described in WO 98/27124 and WO 99/12981 and can be illustrated by [2,6-diaacetylpyridinabis (2,6-diisopropylanyl) FeCl2], 2,6-diaacetylpyridinebis (2,4,6trimethylanil ) FeCl2 and [2,6-diaacetylpyridinebis (2,6-diisopropylanyl) CoCl2].

Other catalysts include Group IIIA derivatives, VAT or Lanthanide metals that are in a formal oxidation state +2, +3 or +4. Preferred compounds include metal complexes containing 1 to 3 anionic or neutral ligand groups that can be cyclic or non-cyclic I-linked anionic ligand groups. Examples of such groups of ligands linked to I are cyclic or non-cyclic, conjugated or unconjugated dienyl groups, allyl groups, boratabenzene groups, phospholo and sand groups. The term linked to I means that the ligand group binds to the metal by sharing electrons from a delocalized I bond.

Each atom in the delocalized I-linked group can be independently substituted with a radical selected from the group consisting of hydrogen, halogen, hydrocarbyl, halohydrocarbyl, hydrocarbyl, substituted metalloid radicals wherein the metalloid is selected from Group IVB of the Periodic Table. The term "hydrocarbyl" includes cyclic, branched and straight C1-C20 alkyl radicals, C6-C20 aromatic radicals, etc. In addition two or more of said radicals together can form a fused ring system or they can form a metallocycle with the metal.

Examples of suitable, anionic, I-linked groups include cyclopentadienyl, indenyl, fluorenyl, tetrahydroindenyl, tetrahydrofluorenyl, octahydrofluorenyl, etc. as well as phospholes and boratabenzene groups.

Phospholes are anionic ligands that are phosphors that contain analogs to cyclopentadienyl groups. These are known in the art and are described in WO 98/50392.

Boratabenzenes are anionic ligands that are boron containing analogs for benzene. These are known in the art and are described in Organometallics, 14, 1, 471-480 (1995).

The preferred polymerization catalyst of the present invention is a bulky ligand compound also referred to as a complex containing at least one of the delocalized I-linked groups mentioned above, in particular cyclopentadienyl ligands. These metallocene complexes are those based on VAT Group metals, for example titanium, zirconium and hafnium.

Metallocene complexes can be represented by the general formula:

LxMQn

where L is a cyclopentadienyl ligand, M is a metal of the IVA Group, Q is a leaving group and x and n are dependent on the oxidation state of the metal.

Normally the metal of the IVA Group metal is titanium, zirconium or hafnium, x is 1 or 2 and typically the leaving groups include halogen or hydrocarbyl. Cyclopentadienyl ligands can be substituted, for example, by alkyl or alkenyl groups or can comprise a fused ring system such as indenyl or fluorenyl.

Examples of suitable metallocene complexes are described in EP 129368 and EP 206794. Such complexes cannot be bridged, for example, bis (cyclopentadienyl) zirconium dichloride, bis (pentamethyl) cyclopentadienyl dichloride, or bridged, for example, ethylene dichloride bis (indenyl) zirconium or dimethylsilyl (indenyl) zirconium dichloride.

Other suitable bis (cyclopentadienyl) metallocene complexes are those bis (cyclopentadienyl) diene complexes described in WO 96/04290. Examples of such complexes are bis (cyclopentadienyl) zirconium (2.3dimethyl-1,3-butadiene) and ethylene bis (indenyl) zirconium 1,4-diphenyl butadiene.

Examples of substituted monocyclopentadienyl or monocyclopentadienyl complexes suitable for use in the present invention are described in EP 416815, EP 418044, EP 420436 and EP 551277. Suitable complexes may be represented by the general formula:

CpMXn

wherein Cp is a single substituted cyclopentadienyl or cyclopentadienyl group optionally covalently bonded to M through a substituent, M is a metal of the VIA Group in a r5 binding mode to the substituted cyclopentadienyl or cyclopentadienyl group, X at each occurrence is hydride or a structural unit selected from the group consisting of halo, alkyl, aryl, aryloxy, alkoxy, alkoxyalkyl, amidoalkyl, siloxyalkyl etc. it has up to 20 non-hydrogen atoms and the neutral Lewis base ligands have up to 20 non-hydrogen atoms or optionally an X together with Cp forms a metallocycle with M and n is dependent on the valence of the metal.

Particularly preferred monocyclopentadienyl complexes have the formula:

where:-

R 'in each occurrence is independently selected from hydrogen, hydrocarbyl, silyl, germyl, halo, cyano, and combinations thereof, said R' has up to 20 non-hydrogen atoms, and optionally, two R 'groups (where R' does not it is hydrogen, halo or cyano) together they form a divalent derivative thereof connected to adjacent positions of the cyclopentadienyl ring to form a fused ring structure;

X is hydride or a structural unit selected from the group consisting of halo, alkyl, aryl, aryloxy, alkoxy, alkoxyalkyl, amidoalkyl, siloxyalkyl etc. it has up to 20 non-hydrogen atoms and the neutral Lewis base ligands has up to 20 non-hydrogen atoms,

And it is -O-, -S-, -NR * -, -PR * -,

M is hafnium, titanium or zirconium,

Z * is SiR * 2, CR * 2, SiR * 2SIR * 2, CR * 2CR * 2, CR * = CR *, CR * 2SIR * 2, or GeR * 2, where:

R * in each occurrence is independently hydrogen, or a member selected from hydrocarbyl, silyl, halogenated alkyl, halogenated aryl, and combinations thereof, said

R * has up to 10 non-hydrogen atoms, and optionally, two R * groups of Z * (when R * is not hydrogen), or an R * group of Z * and an R * group of Y form a ring system., Y

n is 1 or 2 depending on the valence of M.

Examples of suitable monocyclopentadienyl complexes are (tert-butylamido) dimethyl (tetramethyl-r5cyclopentadienyl) silanotitanium dichloride and (2-methoxyphenylamido) dimethyl (tetramethyl-r5-cyclopentadienyl) silanotitanium dichloride.

Other suitable monocyclopentadienyl complexes are those comprising phosphinimine ligands described in WO 99/40125, WO 00/05237, WO 00/05238 and WO 00/32653. A typical example of such a complex is cyclopentadienyl titanium [tri (tertiary butyl) phosphinimine] dichloride.

Another type of polymerization catalyst suitable for use in the present invention are monocyclopentadienyl complexes comprising heteroalyl structural units such as zirconium (cyclopentadienyl) tris (diethylcarbamates) as described in US 5527752 and WO 99/61486.

Particularly preferred metallocene complexes for use in the preparation of the supported catalysts of the present invention can be represented by the general formula:

where:- R ’in each occurrence is independently selected from hydrogen, hydrocarbyl, silyl, germyl, halo, cyano, and combinations thereof, said R 'has up to 20 non-hydrogen atoms, and optionally, two R' groups (in

where R ’is not hydrogen, halo or cyano) together they form a divalent derivative thereof connected to the adjacent positions of the cyclopentadienyl ring to form a fused ring structure; X is a neutral r4 linked diene group having up to 30 non-hydrogen atoms, which forms a complex I with M; And it is -O-, -S-, -NR * -, -PR * -, M is titanium or zirconium in the formal oxidation state + 2;

Z * is SiR * 2, CR * 2, SiR * 2SIR * 2, CR * 2CR * 2, CR * = CR *, CR * 2SIR * 2, or GeR * 2, where:

R * in each occurrence is independently hydrogen, or a member selected from hydrocarbyl, silyl, halogenated alkyl, halogenated aryl, and combinations thereof, said

R * has up to 10 non-hydrogen atoms, and optionally, two R * groups of Z * (when R * is not hydrogen), or an R * group of Z * and an R * group of Y form a ring system.

Examples of suitable X groups include s-trans-r4-1,4-diphenyl-1,3-butadiene, s-trans-r4-3-methyl-1,3-pentadiene; strans-r4-2,4-hexadiene; s-trans-r4-1,3-pentadiene; s-trans-r4-1,4-ditolyl-1,3-butadiene; s-trans-r4-1,4-bis (trimethylsilyl) 1,3-butadiene; s-cis-r4-3-methyl-1,3-pentadiene; s-cis-r4-1,4-dibenzyl-1,3-butadiene; s-cis-r4-1,3-pentadiene; s-cis-r41,4-bis (trimethylsilyl) -1,3-butadiene, said s-cis diene group forming a complex I as defined herein with the metal.

More preferably R 'is hydrogen, methyl, ethyl, propyl, butyl, pentyl, hexyl, benzyl, or phenyl or 2 R' groups (except hydrogen) are joined together, the complete C5R'4 group is therefore, for example, an indenyl, tetrahydroindenyl, fluorenyl, terahydrofluorenyl, or octahydrofluorenyl group.

Highly preferred Y groups are nitrogen or phosphorus containing groups containing a group corresponding to the formula -N (R //) - or -P (R //) - where R // is C1-10 hydrocarbyl.

The most preferred complexes are amidosilane - or amidoalcanidiyl complexes. The most preferred complexes are those where M is titanium. Specific complexes suitable for use in the preparation of the supported catalysts herein

invention are those described in WO 95/00526 and are incorporated herein by reference.

A particularly preferred complex for use in the preparation of the supported catalysts herein. invention is (t-butylamido) (tetramethyl-r5-cyclopentadienyl) dimethyl silanotitanium -r4-1.3 -pentadiene. The charge (transition metal) in the supported catalysts of the present invention is usually in the

range of 0.1 mmol / g to 1 mmol / g. Thus in accordance with a preferred embodiment of the present invention a catalyst system of Supported metallocene prepared by a method comprising the following steps:

(i)

 add a cocatalyst to a porous support,

(ii)

 mixing a metallocene complex with a polymerizable monomer, and

(iii) contact the components together that result from steps (i) and (ii).

Co-catalysts suitable for use in the method of the present invention are those normally used with the polymerization catalysts mentioned above.

These include aluminoxanes such as methyl aluminoxane (MAO), borane such as tris (pentafluorophenyl) borane and borates.

The aluminoxanes are well known in the art and preferably comprise cyclic and / or linear oligomeric alkyl aluminoxanes. The aluminoxanes can be prepared in a number of ways and are preferably prepared by contacting water and a trialkylaluminum compound, for example trimethylaluminum, in a suitable organic medium such as benzene or an aliphatic hydrocarbon.

A preferred aluminoxane is methyl aluminoxane (MAO).

Other suitable cocatalysts are organoboro compounds in particular triarylboro compounds. A particularly preferred triarylboro compound is tris (pentafluorophenyl) borane.

Other suitable compounds such as cocatalysts are compounds comprising a cation and an anion. The cation is normally a Bronsted acid capable of donating a proton and the anion is normally a compatible uncoordinated bulky species capable of stabilizing the cation.

Said co-catalysts can be represented by the formula:

(L * -H) + d (Ad-) where L * is a neutral Lewis base

(L * -H) + d is a Bronsted acid

Ad-is a non-coordinated compatible anion that has a charge of d-, and

d is an integer from 1 to 3.

The cation of the ionic compound can be selected from the group consisting of acidic cations, carbonium cations, silylium cations, oxonium cations, organometallic cations and cationic oxidizing agents. Suitably preferred cations include ammonium cations substituted with trihydrocarbyl for example

triethylammonium, tripropylammonium, tri (n-butyl) ammonium and the like. Also suitable are N, N-dialkylanilinium cations

such as N, N-dimethylanilinium cations. Preferred ionic compounds used as co-catalysts are those where the cation of the compound Ionic comprises an ammonium salt substituted by hydrocarbyl and the anion comprises an aryl substituted borate.

Typical borates suitable as ionic compounds include:

triethylammonium tetraphenylborate

triethylammonium tetraphenylborate,

tripropylammonium tetraphenylborate,

tri (n-butyl) ammonium tetraphenylborate,

tri (t-butyl) ammonium tetraphenylborate,

N, N-dimethylanilinium tetraphenylborate,

N, N-diethylanilinium tetraphenylborate,

trimethylammonium tetrakis (pentafluorophenyl) borate,

triethylammonium tetrakis (pentafluorophenyl) borate,

tripropylammonium tetrakis (pentafluorophenyl) borate,

tri (n-butyl) ammonium tetrakis (pentafluorophenyl) borate,

N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate,

N, N-diethylanilinium tetrakis (pentafluorophenyl) borate.

A preferred type of co-catalyst suitable for use with the metallocene complex of the present invention

comprises ionic compounds comprising a cation and an anion wherein the anion has at least one

substituent comprising a structural unit that has an active hydrogen. Suitable co-catalysts of this type are described in WO 98/27119 whose relevant portions are incorporated herein by reference.

Examples of this type of anion include:

triphenyl (hydroxyphenyl) borate

tri (p-tolyl) (hydroxyphenyl) borate

tris (pentafluorophenyl) (hydroxyphenyl) borate

tris (pentafluorophenyl) (4-hydroxyphenyl) borate

Examples of suitable cations for this type of co-catalyst include triethylammonium, triisopropylammonium, diethylmethylammonium, dibutylethylammonium and the like.

Particularly suitable are those cations having longer alkyl chains such as dihexyldecylmethylammonium, dioctadecylmethylammonium, ditetradecylmethylammonium, bis (hydrogenated bait alkyl) methylammonium and the like.

Particularly preferred cocatalysts of this type are alkylammonium tris (pentafluorophenyl) 4- (hydroxyphenyl) borates. A particularly preferred co-catalyst is bis (hydrogenated bait alkyl) methyl ammonium tris (pentafluorophenyl) (4-hydroxyphenyl) borate.

With respect to this type of co-catalyst, a preferred compound is the reaction product of a tris (pentaflurophenyl) -4- (hydroxyphenyl) borate alkylammonium and an organometallic compound, for example triethylaluminum.

The preferred metal with respect to the organometallic compound is aluminum and the preferred metal for the ionic activator is boron so that the molar ratio of Al / B is less than 2 Y is preferably less than 1 and more preferably in the range of 0.3 to 0.8 .

In a preferred method according to the present invention the molar ratio of the metallocene complex to the cocatalyst employed in the method of the present invention may be in the range of 1: 10,000 to 100: 1. A preferred range is from 1: 5000 to 10: 1 and more preferred from 1:10 to 10: 1.

The supported catalyst systems of the present invention are more suitable for operation in processes that typically employ supported polymerization catalysts.

The supported catalysts of the present invention may be suitable for the polymerization of olefin monomers selected from (a) ethylene, (b) propylene (c) mixtures of ethylene and propylene and (d) mixtures of (a), (b) or (c) with one or more other alpha olefins.

Thus according to another aspect of the present invention there is provided a process for the polymerization of olefin monomers selected from (a) ethylene, (b) propylene (c) mixtures of ethylene and propylene and (d) mixtures of (a), (b) or (c) with one or more other alpha olefins, said process is performed in the presence of a supported polymerization catalyst system as described hereinbefore.

The supported systems of the present invention however are more suitable for use in gas or suspension phase processes.

A suspension process typically uses an inert hydrocarbon diluent and temperatures from about 0 ° C to a temperature just below the temperature at which the resulting polymer becomes substantially soluble in the inert polymerization medium. Suitable diluents include toluene or alkanes such as hexane, propane or isobutane. Preferred temperatures are from about 30 ° C to about 200 ° C but preferably from about 60 ° C to 100 ° C. Circulation reactors are widely used in suspension polymerization processes.

The gas phase processes for the polymerization of olefins, especially for the homopolymerization and copolymerization of ethylene and olefins to for example 1-butene, 1-hexene, 4-methyl-1-pentene are well known in the art.

Typical operating conditions for the gas phase are from 20 ° C to 100 ° C and more preferably from 40 ° C to 85 ° C with pressures from subatmospheric to 100 bar.

Particularly preferred gas phase processes are those that operate in a fluidized bed. Examples of such processes are described in EP 89691 and EP 699213 the latter is a particularly preferred process for use with the supported catalysts of the present invention.

Particularly preferred polymerization processes are those that comprise the polymerization of ethylene.

or the copolymerization of ethylene and olefins having 3 to 10 carbon atoms.

Thus, according to another aspect of the present invention there is provided a process for the polymerization of ethylene or the copolymerization of ethylene and olefins having 3 to 10 carbon atoms, said process is carried out in the present supported catalyst system as described here above.

Preferred olefins are 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene.

The supported catalysts prepared in accordance with the present invention may also be suitable for the preparation of other polymers for example polypropylene, polystyrene, etc.

Through the use of the method of the present invention a free flowing powder is produced which can normally have a similar particle size for the starting porous support material. The resulting supported catalysts are stable at room temperature for extended periods and exhibit a less deactivating kinetic profile than similar catalysts prepared without the incorporation of a polymerizable monomer.

The present invention will be further illustrated with reference to the accompanying examples.

Abbreviations

ASD triethylaluminum

Ionic Compound A [N (H) Me (C18-22H37-45) 2] [B (C6F5) 3 (p-OHC6H4)]

Complex A (C5Me4SiMe2NtBu) Ti (r4-1,3-pentadiene

Example 1

To 10 kg of Grace-Davison 948 silica (previously calcined at 250 ° C for 5 hours) in 110 liters of hexane, 36 liters of 0.5 mol Al / liter of TEA in hexane is added. After 1 hour of stirring at 30 ° C the silica is washed with 130 liters of hexane and dried under vacuum. The concentration of aluminum in the solid is found to be 1.36 mmol / g.

Example 2

To 4.77 ml (0.33 mmol) of a toluene solution of Ionic Compound A (9.1% by weight) 0.795 ml is added

(0.199 mmol) of a TEA toluene solution ([Al] = 0.25 mol / l). This solution is then added to 3.0 g of TEA treated silica (Grace 948, [Al] = 1.36 mmol / g) and the mixture is stirred well until lumps are visible and allowed to stand for 30 min.

To 2.73 ml of 1-hexene (1-hexene / Ti ~ 70 molar ratio) 1.86 ml (0.31 mmol) of a heptane solution of Complex A (8.58% by weight) is added and the mixture is then added to the previous support. The mixture is stirred well for 30 min and finally dried under vacuum. A free flowing green powder is obtained

[Al] = 0.79 mmol / g

[Ti] = 53 mmol / g

Example 3

To 4.77 ml (0.33 mmol) of a toluene solution of Ionic Compound A (9.1% by weight) 0.795 ml is added

(0.199 mmol) of a TEA toluene solution ([Al] = 0.25 mol / l). This solution is then added to 3.0 g of TEA treated silica (Grace 948, [Al] = 1.36 mmol / g) and the mixture is stirred well until lumps are visible and allowed to stand for 30 min.

To 2.73 ml of 1-hexene (1-hexene / Ti ~ 70 molar ratio) 1.86 ml (0.31 mmol) of a heptane solution of Complex A (8.58% by weight) is added and the mixture is allowed to stand for 1 hour before if added to the previous support. The mixture is stirred well for 30 min and finally dried under vacuum. A free flowing green powder is obtained

[Al] = 0.83 mmol / g

[Ti] = 55 mmol / g

Example 4

To 2.42 ml (0.18 mmol) of a toluene solution of ionic Compound A (9.7% by weight) is added 0.43 ml (0.108 mmol) of a toluene solution of TEA ([Al] = 0.25 mol / l). This solution is then added to 3.0 g of TEA treated silica (Grace 948, [Al] = 1.36 mmol / g) and the mixture is stirred well until lumps are visible and allowed to stand for 30 min.

To 0.72 ml of 1-hexene (1-hexene / Ti ~ 34 molar ratio) 1.0 ml (0.167 mmol) of a heptane solution of Complex A (8.58% by weight) is added and the mixture is allowed to stand for 1 hour before if added to the previous support. The mixture is stirred well for 30 min and finally dried under vacuum. A free flowing green powder is obtained

[Al] = 1.08 mmol / g

[Ti] = 46 mmol / g

Example 5

To 2.44 ml (0.18 mmol) of a toluene solution of ionic Compound A (9.7% by weight) is added 0.0.8 ml (0.2 mmol) of a TEA toluene solution ([Al] = 0.25 mol / l). This solution is then added to 3.0 g of TEA treated silica (Grace 948, [Al] = 1.36 mmol / g) and the mixture is stirred well until lumps are visible and allowed to stand for 30 min.

To 0.75 ml of 1-hexene (1-hexene / Ti ~ 34 molar ratio) 1.01 ml (0.169 mmol) of a heptane solution of Complex A (8.58% by weight) is added and the mixture is then added to the previous support. The mixture is stirred well for 30 min and finally dried under vacuum. A free flowing green powder is obtained.

[Al] = 1.11 mmol / g

[Ti] = 46 mmol / g

Example 6

Polymerization series

The support catalyst prepared in Examples 2-5 is tested for copolymerization of ethylene-1-hexene using the following procedure:

A 2.5 l double jacket thermostatic stainless steel autoclave is purged with nitrogen at 70 ° C for at least one hour. 236 g of previously dried PE granules are introduced under vacuum at 80 ° C for 12 hours and the reactor is then purged three times with nitrogen (7 bar at atmospheric pressure). ~ 0.13 g of TEA treated silica (1.5 mmol TEA / g) is added under pressure and the impurities are collected for at least 15 minutes under stirring. The gas phase is then composed (addition of ethylene, 1-hexene and hydrogen) and a mixture of supported catalyst (~ 0.1 g) and silica / TEA (~ 0.1 g) is injected. A constant pressure of ethylene and a constant pressure ratio of ethylene / co-monomer are maintained during the series. The series is terminated by venting the reactor and then the reactor is purged 3 times with nitrogen. The PE powder produced during the series is then separated from the PE seed bed by simple sieving. Typical conditions are as follows:

-

 PC2: 6.5b

-

 C6 / C2 (% vol) = ~ 0.46

-

 H2 / C2 (% vol) = ~ 0.25

-

 T ° = 70 ° C

-

 catalyst added: ~ 100 mg

-

 series duration: 2h

Catalyst

Average activity (2h) 1h activity to

(g / g.h.bar)

(g / g.h.bar)

Example 2

60 78

(continuation)

Catalyst

Average activity (2h) 1h activity

(g / g.h.bar)

(g / g.h.bar)

Example 3

58 73

Example 4

60 79

Example 5

61 78

These examples clearly show that premixing the titanium complex with 1-hexene before addition to the support generates highly active catalyst systems for the polymerization of ethylene with a slow activity reduction profile. No agglomeration of catalyst particles.

Claims (16)

1. A supported polymerization catalyst system prepared by a method comprising the following steps:

(i)

 add a cocatalyst to a porous support,

(ii)

mixing a polymerization catalyst with a polymerizable monomer, and

(iii) contact the components together that result from steps (i) and (ii) wherein the ratio of the polymerizable monomer to the polymerization catalyst is in the range of 1: 1 to 250: 1.

2.

A supported polymerization catalyst system according to claim 1 wherein the porous support is an inorganic metal oxide.

3.

A supported polymerization catalyst system according to claim 2 wherein the inorganic metal oxide is silica.

Four.

A supported polymerization catalyst system according to any of the preceding claims wherein the polymerizable monomer has 2 to 10 carbon atoms.

5.

A supported polymerization catalyst system according to claim 4 wherein the monomer is 1-hexene.

6.

A supported polymerization catalyst system according to any of the preceding claims wherein the polymerization catalyst is a transition metal compound.

7.

A supported polymerization catalyst system according to claim 6 wherein the transition metal compound is a metallocene.

8.

A supported polymerization catalyst system according to claim 7 wherein the metallocene has the formula

where:- R 'in each occurrence is independently selected from hydrogen, hydrocarbyl, silyl, germyl, halo, cyano, and combinations thereof, said R' has up to 20 non-hydrogen atoms, and optionally, two R 'groups (where R' does not it is hydrogen, halo or cyano) together they form a divalent derivative thereof connected to adjacent positions of the cyclopentadienyl ring to form a fused ring structure; X is hydride or a structural unit selected from the group consisting of halo, alkyl, aryl, aryloxy, alkoxy, alkoxyalkyl, amidoalkyl, siloxyalkyl etc. it has up to 20 non-hydrogen atoms and the neutral Lewis base ligands have up to 20 non-hydrogen atoms, And it is -O-, -S-, -NR * -, -PR * -, M is hafnium, titanium or zirconium, Z * is SiR * 2, CR * 2, SiR * 2SiR * 2, CR * 2CR * 2, CR * = CR *, CR * 2SiR * 2, or GeR * 2, where: R * in each occurrence is independently hydrogen, or a member selected from hydrocarbyl, silyl, halogenated alkyl, halogenated aryl, and combinations thereof, said R * has up to 10 non-hydrogen atoms, and optionally, two R * groups of Z * (when R * is not hydrogen), or an R * group of Z * and an R * group of Y form a ring system, and n It is 1 or 2 depending on the valence of M. 9. A supported polymerization catalyst system according to claim 7 wherein the metallocene has the formula where:- R1 at each occurrence is independently selected from hydrogen, hydrocarbyl, silyl, germyl, halo, cyano, and combinations thereof, said R 'has up to 20 non-hydrogen atoms, and optionally, two R' groups (where R 'is not hydrogen, halo or cyano) together form a divalent derivative thereof connected to adjacent positions of the cyclopentadienyl ring to form a fused ring structure; X is a neutral r4 linked diene group having up to 30 non-hydrogen atoms, which forms a complex I with M; And it is -O-, -S-, -NR * -, -PR * -, M is titanium or zirconium in the formal oxidation state + 2; Z * is SiR * 2, CR * 2, SiR * 2SiR * 2, CR * 2CR * 2, CR * = CR *, CR * 2SiR * 2, or GeR * 2, where: R * in each occurrence is independently hydrogen, or a member selected from hydrocarbyl, silyl, halogenated alkyl, halogenated aryl, and combinations thereof, said R * has up to 10 non-hydrogen atoms, and optionally, two R * groups of Z * (when R * is not hydrogen), or an R * group of Z * and an R * group of Y form a ring system.

10.

A supported polymerization catalyst system according to any of the preceding claims wherein the cocatalyst is an aluminoxane, borane or borate.

eleven.

A supported polymerization catalyst system according to any of the preceding claims wherein the cocatalyst has the formula

(L * -H) + d (Ad-) where L * is a neutral Lewis base (L * -H) + d is a Bronsted acid Ad- is a non-coordinated compatible anion that has a charge of d-, and d is an integer from 1 to 3.

12.

A supported polymerization catalyst system according to claim 11 wherein the cocatalyst comprises a cation and an anion wherein the anion has at least one substituent comprising a structural unit having an active hydrogen.

13.

A process for the polymerization of olefin monomers selected from (a) ethylene, (b) propylene (c) mixtures of ethylene and propylene and (d) mixtures of (a), (b) or (c) with one or more of other alpha olefins, said process is performed in the presence of a supported polymerization catalyst system as claimed in any of the preceding claims.

14. A process according to claim 13 for the polymerization of ethylene or the copolymerization of ethylene and olefins having 3 to 10 carbon atoms, said process is carried out under polymerization conditions in the presence of a catalyst system of polymerization as claimed in claims 1 to 12. 15. A process according to claim 14 wherein the olefin a is 1-butene, 1-hexene, 4-methyl-1-pentene or 1-octene. 16. A process according to any of claims 13 to 15 is carried out in the gas or suspension phase.

17.

A process according to claim 16 is carried out in a fluidized bed gas phase reactor.

18.

A supported polymerization catalyst system according to claim 1 wherein the ratio of the polymerizable monomer to the polymerization catalyst is in the range of 20: 1 to 80: 1.